The clinical program core will provide tissue material from surgically excised breast cancers, benign breast tissue, skin and when available, metastatic disease in lymph nodes. Fines needle aspiration material from benign breast disease and disseminated metastatic breast cancer in superficial locations will also be collected and processed for distribution to the two other project cores for subsequent processing, analysis, and distribution to the subprojects. The research goals of this program will include administering three clinical protocols designed to 1) identify prognostic parameters, using surgically-excised primary breast cancer specimens; 2) identify malignant risk factors within benign breast tumors using fine needle aspiration (FNA); and 3) develop protocols using FNA for monitoring chemotherapy response.